Limitations of C-urea Breath Test (ubt) and Stool Antigen Test (sat) in Diagnosis of Helicobacter Pylori (hp) Infections

Helicobacter pylori (HP)(1) management (including diagnosis and therapy) has been exhaustively reviewed in several reports. These reports are unanimous in that several clinical conditions seriously hamper the diagnostic value of two HP tests: 13 C-Urea Breath Test (UBT) and Stool Antigen test (SAT), because of the false-negative results frequently (up to 40%) obtained in these conditions. Basically, these false-negative results are due to decreased bacterial loads in the stomach mucosa, and include the following clinical conditions: 1) use of PPI medication; 2) use of antibiotics; 3) bleeding peptic ulcer; 4) atrophic gastritis (with or without intestinal metaplasia); 5) gastric cancer; 6) MALT lymphoma, and 7) partial gastrectomy. Since the late 1990’s, it has been well established that UBT also gives falsepositive results in cases where urease-producing bacterial species are colonizing an achlorhydric stomach due to atrophic gastritis or a long term use of proton pump inhibitors (PPIs).